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What is the difference between NaN and None?
I am reading two columns of a csv file using pandas readcsv() and then assigning the values to a dictionary. The columns contain strings of numbers and letters. Occasionally there are cases where a cell is empty. In my opinion, the value read to that dictionary entry should be None but instead ...
SQL “select where not in subquery” returns no results
...emantically the same.
When it is nullable, NOT IN is different, since IN (and, therefore, NOT IN) return NULL when a value does not match anything in a list containing a NULL.
This may be confusing but may become more obvious if we recall the alternate syntax for this:
common_id = ANY
(
SELECT c...
PHP: How to generate a random, unique, alphanumeric string for use in a secret link?
How would it be possible to generate a random, unique string using numbers and letters for use in a verify link? Like when you create an account on a website, and it sends you an email with a link, and you have to click that link in order to verify your account
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Differences between MySQL and SQL Server [closed]
...ho has used Microsoft SQL Server for all my database needs (both at work and for personal projects).
12 Answers
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Where is the “Fold” LINQ Extension Method?
... prod * next);
See MSDN for more information. It lets you specify a seed and then an expression to calculate successive values.
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Reference - What does this error mean in PHP?
This is a number of answers about warnings, errors, and notices you might encounter while programming PHP and have no clue how to fix them. This is also a Community Wiki, so everyone is invited to participate adding to and maintaining this list.
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Importing variables from another file?
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from file1 import *
will import all objects and methods in file1
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Ball to Ball Collision - Detection and Handling
...y mass, the new velocities can be calculated using the equations (where v1 and v2 are the velocities after the collision, and u1, u2 are from before):
If the balls have the same mass then the velocities are simply switched. Here's some code I wrote which does something similar:
void Simulati...
How do Mockito matchers work?
Mockito argument matchers (such as any , argThat , eq , same , and ArgumentCaptor.capture() ) behave very differently from Hamcrest matchers.
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What is 'Pattern Matching' in functional languages?
I'm reading about functional programming and I've noticed that Pattern Matching is mentioned in many articles as one of the core features of functional languages.
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